Splenic Hemangiosarcoma in a Young Sprague-Dawley Rat

The present report describes a rare case of spontaneous hemangiosarcoma in a nine-week-old male Sprague-Dawley rat. At necropsy, multiple white nodules of various sizes were observed on and within the enlarged spleen and liver and were histopathologically determined to be composed of spindle- to oval-shaped cells that showed invasive growth without encapsulation and were arranged solidly but partially in whorls or faint alveolar patterns with vascular-like spaces containing small clefts or erythrocytes in the tumor mass. Immunohistochemical analysis revealed that most of the tumor cells were strongly positive for vimentin, von Willebrand factor (vWF) and CD34 but negative for podoplanin. In addition, electron microscopic examination revealed the presence of Weibel-Palade bodies in the cytoplasm of the tumor cells. Based on these findings, this case was diagnosed as a hemangiosarcoma. The splenic masses were larger than the hepatic ones, with tumor cells mainly observed at periportal regions with tumor embolism in the liver, suggesting that primary hemangiosarcoma initially developed in the spleen before metastasizing.     

Complex apocrine carcinoma with dominant myoepithelial proliferation in a dog

A rare case of complex apocrine carcinoma displaying dominant myoepithelial proliferation developed in the right leg subcutis of a 10-year-old male dog. The major cell population consisted of diffusely proliferating p63-expressing neoplastic cells that were largely myoepithelial in origin co-expressing α-smooth muscle actin. A small portion of the cell population consisted of concomitant basal epithelial cells lacking α-smooth muscle actin expression. The minor population consisted of p63-negative apocrine gland cells that expressed cytokeratin 8. The myoepithelial cell population showed a rather stronger proliferation activity than did the apocrine epithelial population. Thus, this tumor might have been derived from basal epithelial cells characterized by more predominant myoepithelial differentiation than luminal apocrine epithelial differentiation.     

Peripheral mononuclear cell response in Japanese black calves after oral administration of IFN-alpha

To investigate the effects of oral administration of an interferon (IFN)-alpha drug on the immune reaction of healthy Japanese Black (JB) calves, peripheral leukocyte populations and their ability to produce cytokine mRNA were analyzed after oral administration of IFN-alpha. Fourteen calves fed in one herd were divided into two groups; seven calves were orally administered 0.1 g/day of IFN-alpha from the day of birth to day 5 on each day (group 1, N=7), and the other seven calves were used as the control (group 2, N=7). Blood samples were collected from the jugular veins of all calves before administration and in weeks 1, 2, 4, 8, and 16 after birth. The number of MHC class II+CD14+ monocytes in the leukocytes population of group 1 increased gradually after birth, and significantly higher numbers were detected in week 4 compared with group 2. MHC class II-CD14+ monocytes in group 1 peaked in week 1, and a significant increase was detected compared with group 2. The level of IL-12 in the cytokine mRNA of group 1 increased gradually between weeks 1 and 2, and a significantly higher level of IL-12 was found compared with group 2. These results suggest that oral administration of IFN-alpha induces activation of the monocyte functions in JB calves.     

A spontaneous thymic carcinosarcoma in a young Sprague Dawley rat

We encountered a case of spontaneous thymic carcinosarcoma in a young Crl:CD (Sprague Dawley) rat. Grossly, a white multinodular mass replaced the thymus in the thoracic cavity. Histologically, multiple nodules were separated by fibrous stroma, and each nodule included isolated regions that were composed of epithelial or non-epithelial tumor cells. The epithelial tumor cells were relatively large and round to polygonal cells with large nuclei and weakly eosinophilic cytoplasm. These cells were cytokeratin-positive and vimentin-negative. These cells infiltrated the lungs. The non-epithelial tumor cells were poorly differentiated, small, round to spindle-shaped cells with small nuclei and basophilic cytoplasm. These cells were vimentin-positive and mostly cytokeratin-negative. Many islands of cartilage were observed near non-epithelial cells. Based on these findings, the tumor was diagnosed as a primary thymic carcinosarcoma consisting of a malignant thymoma composed of epithelial tumor cells and a mesenchymal chondrosarcoma composed of non-epithelial tumor cells.     

Holmium:YAG Laser Lithotripsy for Urolithiasis in Horses

Background: Laser lithotripsy has been used as an alternative to surgical removal of uroliths.
Objective: To describe the procedure and efficacy of laser lithotripsy for removal of lower urinary tract uroliths in horses. Additionally, the ultrastructure and the differences in mineralogy and microstructure from 1 successful and 1 unsuccessful laser lithotripsy case are described.
Animals: Six client-owned horses with 7 episodes of naturally occurring urocystoliths, urethroliths, or both.
Methods: Retrospective study of all horses treated between 2006 and 2008 by laser lithotripsy. All horses were sedated followed by laser lithotripsy. Quantitative urolith analysis was performed in all cases. Ultrastructure and microstructure analyses were performed on uroliths from 2 horses.
Results: Procedural success was achieved in 5 of 7 laser lithotripsy procedures. No complications occurred as a result of laser lithotripsy. One horse developed uroabdomen likely as a result of manual lithotrite disruption of the bladder after failure of laser lithotripsy. There were differences in microstructure between 1 urolith that was successfully fragmented by laser lithotripsy and 1 urolith that was resistant to laser fragmentation.
Conclusions and Clinical Importance: Laser lithotripsy is an effective procedure for removal of some urocystoliths, urethroliths, or both in horses.